Short option for no-confirm flag (rust-lang#540)

Add short name for no-confirm flag

Closes rust-lang#536

The -y short name is a convention, often used by package managers (apt, yum, ...) and it is associated with a request of no interaction (thus often used in scripts, to automate workflows)

crates/bin/src/args.rs

@@ -157,7 +157,7 @@ pub struct Args {
     pub dry_run: bool,
 
     /// Disable interactive mode / confirmation prompts.
-    #[clap(help_heading = "Options", long)]
+    #[clap(help_heading = "Options", short = 'y', long)]
     pub no_confirm: bool,
 
     /// Do not cleanup temporary files.